Transmission mechanism for tractors



March 25, 1930. G. w. ENGS TROM TRANSMISSION MECHANISM FOR TRACTORSOriginal Filed July 28. 19.22 2 Sheets-Sheet 1 jnzieni'vz". ZUK595520271,

' fl y March 25, 1930. e. w.- ENGSTROM 1,751,579

TRANSMISSION MECHANISM FOR TRACTORS Original Filed July 28. 1922 2Sheets-Sheet 2 IIIIJ-ZIYZ'UT? G/ uj af ZZIEZgp ZmIn,

1 5 W W fl y Patented Mar. 25, 1930 UNITED STATES PATENT OFFICE GUSTAI'W. ENGSTROM; OI RIVERSIDE, ILLINOIS, ASSIGNOR TO INTERNATIONAL HARVESTERCOMPANY, A CORPORATION OF NEW JERSEY I TRANSMISSION MECHANISM FORTRAGTORS Original application filed July 88, 1922, Serial No. 578,071.Divided and this Serial No. 84,784.

This invention relates to tractors and particularl to a transmissionmechanism therefor. Mbre particularly it relates to a transmissionmechanism for a steam propelled tractor of the type disclosed in mycopending application filed July 28, 1922,bearin Serial No. 578,071, ofwhich the present application is a division.

It is an object of this inventionto provide a simple and compacttransmission mechanism for a tractor, and particularly for a steamtractor, which will enable such tractors to be constructed in smallsizes of equal or greater power and of less first cost and operatingexpense than correspondingly sized gas engine tractors now commonly inuse.

Another object is so to mount an engine with respect to a differentialtransmission mechanism carried on the axle of a tractor as to permit acompact arrangement with a minimum of parts without sacrificing the ef-'ficiency thereof.

Other objects will be apparent to those skilled in this art as thedescription progresses.

These objects are briefly accomplishedinthe combination with a tractorhaving the usual stub axles carrying the rear wheels of such tractor, ofa transmission mechanism embodying a difi'erential for impartingrotation to such stub axles, said transmisslon being directly geared tothe stub axles and enclosed in a casing supporting directly thereover anengine havin a crank shaft parallell arranged with t e stub axles andgeared t erewith for imparting rotative movement thereto.

The preferred embodiment of the invention is illustrated intheaccompanying sheet of drawings, like characters of reference denotinglike parts throughout the views, and wherein,

Fig. 1 is an end elevation of the engine and transmission carried on thetractor axles; and

Fig. 2 is asection of the mechanism shown in Fig. 1 taken along thesectional line 2-2, Eaoking in the direction of the arrows in said re.'l he tractor, not shown, has a pair of conventional, aligned stub axles10 each of which has keyed thereto for rotation therewith the usual reartractor supporting and driving applicationflled June 4, 1925.

wheels 11, the stub axles being journaled in a v 2 .transmission anddifferential casing 12 supported thereon. Directly above the casing 121s a caslng 1 3 comprising1 the crank case of a driving engine, and in te present preferred embodiment is a uniflow engine of the V type Ihaving cylinders 14 arranged on each side of the crank case. The crankcase has journaled therein a crank shaft 15 arranged in parallel withthe stub axles 1O of'the tractor and substantially thereabove, saidcrank shaft having the usual fly wheel and belt pulley 16 thereonoutside of the casing 13, the crank shaft receiving its rotativemovement in a conventlonal manner by means of connecting rods 17operable by pistons, not shown, and reclprocable Within the cylinders14;. The crank case 13, it will be observed, is bolted to thetransmission and differential casing 12 and directly thereover, so thatthe entire weight thereof bears down on the axles and is supported bythe rear wheels 11 in a very compact manner and to the end that suchwheels 11 will have a greater tractive effort.

The crank shaft carries at its end away from the fly wheel 16 a gear 18which meshes with a gear 19 journaled on a differential shaft 20, saidgear 19 being provided with a clutch element 21'adapted to engage acorresponding clutch element 22 on a diiferential drum 23, said drumhousing a conventional. differential gear mechanism 24 connecting theshaft 20 and a second differential shaft 25 in common axial alignmenttherewith. The differential shafts are provided on their outer ends withpinions 26 and 27, which respectively mesh with gears 28 and 29 keyed tothe stub axles 10 for drivin the rear tractor supporting wheels 11. .T eclutch 21 is provided with a groove 30 adapted to be engaged by ashipper fork 31 secured to an arm 32 fast on a rock shaft 33, which maybe rocked by means of a hand lever 34 for engaging ordisengaging theclutch. A spring pressed detent 35 engages the arm 32 to retain theclutch in engaged or disengaged positions in any suitable manner. Itwill be observed that the difierential shaft 20- is extended ceiving abrake drum or other raking mech 'anism, not shown, for imparting abrakin action directl to the transm1ssion. The d1 ferential shafts arejournaled at their outer ends in bearin cages 36, as shown.

From the above disclosure it is apparent that the object of providing acompact and simple drivln arrangement for a tractor and particularly orone driven by a steam engine has been attained. The transmission anddifierential casing 12 and crank case 13 provide lubricant containingchambers for thereabove, and an engine drivingly connected to thedifierential mechanism and located directly thereabove. V

6. In a driving mechanism for a tractor having a main transmissionincluding a differentlal having a pair of differential shafts, a housingtherefor including two spaced depending parts, a stub axle protrudingfrom each depending housing part, gearing connecting the stub shaftswith the difierential shafts, said transmission housing-being locatedvertically above the stub axles, and an engine unit including a crankshaft geared the engine and driving connections to the rear to the maintransmission, said engine unit wheels as will be apparent.

As various possible embodiments might be made of the above invention andas various changes might be made in the particular embodiment set forth,it is to be understood that all matter herein shown and disclosed is'tobe interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. The combination with an engine having a crank case, of a transmissioncasing on to ofwhich the crank case is mounted, a cran shaft journaledin the crank case and having a gear fixed thereon, two differentialshafts journaled in the transmission casing, differential gearingconnecting the differential shafts, a driving gear rotatably mounted onone of the differential shafts, a clutch adapted to connect the drivinggear and diiferential gearin means for operating the clutch, two spacestub axles journaled in opposite sides of the transmission casing, agear on each stub axle, and a gear on each difierential shaft in meshwith each gear on the stub axles.

2. The combination in a tractor having a wheel supported rear axle, of adifierential casing supported on and abovesaid axle, difierentialgearing in said casing, an engine including a crank case and a crankshaft mounted on and directly above the differential casing, andoperative connections between the crank shaft, differential gearing, andthe axle.

3. In a tractor havin a wheel supported rear axle, the combination of adifferential mechanism located substantially above said axle, and anengine for driving said difierential mechanism located substantiallyabove said differential mechanism.

4. In a driving mechanism for a tractor having awheel sup orted rearaxle, a transmission unit includlng a differential, an engine, thetransmission unit located on and substantially vertically above theaxle, and

the en ne located on and substantially vertically a ove the transmissionunit.

. 5. In a driving mechanism for a tractor having a pair of wheelsupported rear stub axles, the combination of a differential mechanlsmconnected to said axles and located located on and vertically above thetransmission housing. v

In testimon whereof I aflix m signature.

USTAF W. EN STROM.

